by Paul Myerberg, USA TODAY Sports

by Paul Myerberg, USA TODAY Sports

Heisman Trophy campaigns are created during the offseason and fed in September, when teams feast on non-conference competition, but true Heisman contenders don't take flight until October, when the FBS turns to conference play. It's in October and November that Johnny Manziel won last year's Heisman; likewise with former Baylor quarterback Robert Griffin III, who did not become the frontrunner until after the Bears turned the corner against the Big 12's elite.

So there may very well be a dark horse somewhere in the SEC, Big Ten, Pac-12 or elsewhere, a player excelling in the shadows poised to make a national statement during conference play. Is it too late for an under-the-radar star to leapfrog ahead of a Manziel, McCarron, Murray or Mariota and claim the 2013 Heisman? One thing is certain: With no clear favorite as the opening month comes to a close, there is every reason to think this year's competition won't be settled until deep into November.

With five weeks of the 2013 season in the books, here are 10 leading contenders for the Heisman:

Manziel will remain atop the list until another player shines on a big stage against a title-worthy opponent â?? because his performance against Alabama, even in a loss, was the top individual game by a quarterback during the opening month.

Boyd has that win against Georgia in his pocket, which should help him remain above Aaron Murray despite the latter's big-game heroics against South Carolina and LSU. Boyd's candidacy rests on his performance against Florida State on Oct. 19.

4. Georgia QB Aaron Murray (Last week's ranking: No. 6)

Season stats: 79-of-116 for 1,338 yards; 11 touchdowns, three interceptions

Remember when Murray was taken to task â?? unfairly, of course â?? for failing to win the big games on Georgia's schedule? We won't hear that line again, thankfully.

5. Alabama QB AJ McCarron (Last week's ranking: No. 4)

Season stats: 75-of-110 for 882 yards; six touchdowns, three interceptions

McCarron should land a spot in Manhattan as a Heisman finalist if Alabama runs the table, but his numbers still lag behind the leading contenders. He has another opportunity to impress the voters against LSU in November.

6. UCLA QB Brett Hundley (Last week's ranking: No. 7)

Season stats: 61-of-92 for 848 yards; eight touchdowns, three interceptions; 32 carries for 157, two touchdowns

The Bruins, idle Saturday, commence Pac-12 play Thursday night at Utah. Whether Hundley can remain on the outskirts of the Heisman race demands wins against teams like Utah and California, but his candidacy hinges on two road games in particular: Stanford on Oct. 19, Oregon on Oct. 26.

7. Louisville QB Teddy Bridgewater (Last week's ranking: No. 5)

Season stats: 79-of-110 for 1,214 yards; 14 touchdowns, one interception

That Louisville misses any major contenders on the road to a BCS berth is good for the Cardinals, but the lack of marquee competition hurts Bridgewater's chances at the Heisman. But when all is said and done, his numbers might be too good to ignore.

Let's remember that Winston's only a redshirt freshman. He's playing far beyond his years, adding a dose of the running game to his strong passing skills in Saturday's win against Boston College, and his end-of-the-first-half touchdown heave was the sort of highlight-reel moment all Heisman campaigns demand.

9. Ohio State QB Braxton Miller (Last week's ranking: Unranked)

Season stats: 34-of-49 for 406 yards; six touchdowns, one interception; 40 carries for 165 yards

Saturday's win against Wisconsin was Miller's welcome-back moment: Forgotten after a knee injury robbed him of two games during non-conference play, his performance was a reminder that Miller needs to remain a fixture in the Heisman conversation.

10. Fresno State QB Derek Carr (Last week's ranking: Unranked)

Season stats: 146-of-211 for 1,445 yards; 14 touchdowns, three interceptions

Carr deserves some recognition for his consistently steady play during Fresno State's perfect start, a run that included an enormous 41-40 win against Boise State. The numbers are there, but Carr needs help: A few of the names ahead of the senior in the Heisman race need to stumble in October and November.

Paul Myerberg, a national college football writer for USA TODAY Sports, is on Twitter @PaulMyerberg.